Activating Compound | Comment | Organism | Structure |
---|---|---|---|
benzoic acid | 134% relative activity at 10 mM | Pouteria sapota | |
Citric acid | 148% relative activity at 10 mM | Pouteria sapota | |
potassium sorbate | 158% relative activity at 10 mM | Pouteria sapota |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
ascorbic acid | one of the most effective inhibitors of isozyme PPO 1, complete inhibition at 0.1 mM | Pouteria sapota | |
EDTA | 5% residual activity at 0.1 mM | Pouteria sapota | |
kojic acid | 43% residual activity at 1 mM | Pouteria sapota | |
NaCl | 29% residual activity at 0.1 mM | Pouteria sapota | |
Sodium metabisulfite | one of the most effective inhibitors of isozyme PPO 1, complete inhibition at 0.1 mM | Pouteria sapota | |
succinic acid | complete inhibition at 1 mM | Pouteria sapota | |
tropolone | 68% residual activity at 0.1 mM | Pouteria sapota |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
1.3 | - |
pyrogallol | isozyme PPO 1, in 0.2 M sodium phosphate buffer pH 7.0, 25°C | Pouteria sapota | |
44 | - |
catechol | isozyme PPO 1, in 0.2 M sodium phosphate buffer pH 7.0, 25°C | Pouteria sapota |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
16100 | - |
gel filtration | Pouteria sapota |
18000 | - |
1 * 18000, SDS-PAGE | Pouteria sapota |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Pouteria sapota | - |
mamey | - |
Purification (Comment) | Organism |
---|---|
ammonium sulfate precipitation, and phenyl Sepharose column chromatography | Pouteria sapota |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
fruit | - |
Pouteria sapota | - |
Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|
1.32 | - |
crude extract, at pH 7.0, 25°C | Pouteria sapota |
8.76 | - |
isozyme PPO 1 after 6.6fold purification, at pH 7.0, 25°C | Pouteria sapota |
241.5 | - |
isozyme PPO 2 after 183fold purification, at pH 7.0, 25°C | Pouteria sapota |
Storage Stability | Organism |
---|---|
isozyme PPO 2 is highly unstable such as after 24 h of storage PPO 2 activity is not detected | Pouteria sapota |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
2 catechol + O2 | 100% activity with 10 mM substrate concentration | Pouteria sapota | 2 1,2-benzoquinone + 2 H2O | - |
? | |
4-methylcatechol + O2 | 208% activity with 10 mM substrate concentration compared to catechol | Pouteria sapota | 4-methyl-1,2-benzoquinone + H2O | - |
? | |
additional information | the enzyme shows no activity towards caffeic acid, DL-Dopa, ferulic acid and phenol | Pouteria sapota | ? | - |
? | |
pyrogallol + O2 | 746% activity with 10 mM substrate concentration compared to catechol | Pouteria sapota | ? | - |
? |
Subunits | Comment | Organism |
---|---|---|
monomer | 1 * 18000, SDS-PAGE | Pouteria sapota |
Synonyms | Comment | Organism |
---|---|---|
polyphenol oxidase | - |
Pouteria sapota |
PPO 1 | isozyme | Pouteria sapota |
PPO 2 | isozyme | Pouteria sapota |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
35 | 45 | optimum temperature for isozyme PPO 1 | Pouteria sapota |
Temperature Minimum [°C] | Temperature Maximum [°C] | Comment | Organism |
---|---|---|---|
20 | 70 | at 20°C the residual activity (26%) is maintained, at higher temperatures the activity decreases (50-60°C) and from 65 to 70°C there is no activity | Pouteria sapota |
Temperature Stability Minimum [°C] | Temperature Stability Maximum [°C] | Comment | Organism |
---|---|---|---|
35 | - |
PPO is maximum thermally stable up to 35°C | Pouteria sapota |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7 | - |
optimum pH for isozyme PPO 1 | Pouteria sapota |
pH Minimum | pH Maximum | Comment | Organism |
---|---|---|---|
6 | 7.5 | at pH 6.0, isozyme PPO 1 activity increases drastically, reaching maximum activity at pH 7.0 and then again radically decreases at pH 7.5 | Pouteria sapota |